1. Technical Field
The present invention relates to a semiconductor memory card which performs contactless communication with a reader/writer.
2. Background Art
A system which employs a semiconductor memory card (contactless semiconductor memory card) which performs contactless communication with a reader/writer has been used in wide range of fields such as mass media, financial institutions, governments, and municipalities. It is because of the convenience and security of the contactless semiconductor memory card. Specifically, it is convenient for a user that the user can enjoy a service only by passing the contactless semiconductor memory card over the IC card reader/writer, that is, only by bringing it closer to the reader/writer. Also, in order to receive a service, the security is secured that the user does not need to present confidential information in the IC card to the outside. As such contactless semiconductor memory card, a typical example is a contactless IC card (hereafter it may be simply referred to as “IC card”).
FIG. 1 is a drawing showing usage patterns of a general IC card. A user can enjoy a service only by passing IC card 110 over reader/writer 106. Even if the IC card is passed over reader/writer 106 while keeping IC card 110 in a purse or a bag or connecting IC card 110 to portable device 107, the user can enjoy the similar service as in the case of using the IC card itself.
FIG. 2 is a diagram showing a hardware structure of the general IC card. The IC card includes antenna coil 310, ROM 301, RAM 302, CPU 303, Electrically Erasable Programmable Read Only Memory (EEPROM) 304. Antenna coil 310 receives power supply from an external device, and communicates with the external device. ROM 301 stores a program. RAM 302 temporally stores data used for executing a program. CPU 303 controls various command processing according to the program stored in ROM 301. EEPROM 304 is a rewritable memory, in which a program downloaded from the outside is stored.
In general, as a characteristic of the IC card, not to mention that the IC card has larger memory storage than a magnetic card, it can be said that the security function for personal information and the like stored in the IC card is tightened.
Conventionally, the service realized by a single IC card had been a single service such as electronic money. However, in recent years, it has been proposed to realize more than one services using single IC card due to increases of memory storage in the IC card and of processing speed of CPU in the IC card.
Consequently, the user can enjoy various services using single IC card without having many different IC cards. Thus, multiple applications are installed in the IC card corresponding to multiple services. Therefore, hereafter, the IC card corresponding to multiple services may be referred to as “multi-application IC card”.
FIG. 3 is a diagram showing a software structure of the general IC card. Software of IC card 110 has a three-layered structure. The bottom layer has memory area 405 for application programs; the middle layer has OS 404; and the top layer has at least one application program.
Here, it is shown as an example that in the top layer, there are i numbers of EC client application programs (C_E_APL) 401, 402, . . . , and 40i. These C_E_APL 401, 402, . . . , and 40i respectively correspond to i numbers of EC server application programs (E_APL) 101, 102, . . . , and 10i that are not shown in the diagram.
Thus, each application program corresponds to each service. Therefore, hereafter, the application program may be referred to as a “service”.